6 files changed, 40 insertions, 2 deletions
diff --git a/Library/Homebrew/build_options.rb b/Library/Homebrew/build_options.rb
index e9a06f4e0..1c44af147 100644
--- a/Library/Homebrew/build_options.rb
+++ b/Library/Homebrew/build_options.rb
@@ -101,6 +101,15 @@ class BuildOptions
     @options - @args
   end
 
+  # @private
+  def invalid_options
+    @args - @options
+  end
+
+  def invalid_option_names
+    invalid_options.map(&:flag).sort
+  end
+
   private
 
   def option_defined?(name)
diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index 402a159db..aa316b187 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -261,7 +261,9 @@ module Homebrew
     f.print_tap_action
 
     fi = FormulaInstaller.new(f)
-    fi.options             = f.build.used_options
+    build_options          = f.build
+    fi.options             = build_options.used_options
+    fi.invalid_opt_names   = build_options.invalid_option_names
     fi.ignore_deps         = ARGV.ignore_deps?
     fi.only_deps           = ARGV.only_deps?
     fi.build_bottle        = ARGV.build_bottle?
diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 09c11318e..f678acaf8 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -32,7 +32,7 @@ class FormulaInstaller
   end
 
   attr_reader :formula
-  attr_accessor :options, :build_bottle
+  attr_accessor :options, :build_bottle, :invalid_opt_names
   mode_attr_accessor :show_summary_heading, :show_header
   mode_attr_accessor :build_from_source, :force_bottle
   mode_attr_accessor :ignore_deps, :only_deps, :interactive, :git
@@ -52,6 +52,7 @@ class FormulaInstaller
     @quieter = false
     @debug = false
     @options = Options.new
+    @invalid_opt_names = []
 
     @@attempted ||= Set.new
 
@@ -214,6 +215,10 @@ class FormulaInstaller
       opoo "#{formula.full_name}: #{old_flag} was deprecated; using #{new_flag} instead!"
     end
 
+    invalid_opt_names.each do |option|
+      opoo "#{formula.full_name}: #{option} is invalid for this formula and will be ignored!"
+    end
+
     oh1 "Installing #{Formatter.identifier(formula.full_name)}" if show_header?
 
     if formula.tap && !formula.tap.private?
diff --git a/Library/Homebrew/test/test_build_options.rb b/Library/Homebrew/test/test_build_options.rb
index dab418792..02f4be0fa 100644
--- a/Library/Homebrew/test/test_build_options.rb
+++ b/Library/Homebrew/test/test_build_options.rb
@@ -7,6 +7,8 @@ class BuildOptionsTests < Homebrew::TestCase
     args = Options.create(%w[--with-foo --with-bar --without-qux])
     opts = Options.create(%w[--with-foo --with-bar --without-baz --without-qux])
     @build = BuildOptions.new(args, opts)
+    bad_args = Options.create(%w[--with-foo --with-bar --without-bas --without-qux --without-abc])
+    @bad_build = BuildOptions.new(bad_args, opts)
   end
 
   def test_include
@@ -31,4 +33,17 @@ class BuildOptionsTests < Homebrew::TestCase
   def test_unused_options
     assert_includes @build.unused_options, "--without-baz"
   end
+
+  def test_invalid_options
+    assert_empty @build.invalid_options
+    assert_includes @bad_build.invalid_options, "--without-bas"
+    assert_includes @bad_build.invalid_options, "--without-abc"
+    refute_includes @bad_build.invalid_options, "--with-foo"
+    refute_includes @bad_build.invalid_options, "--with-baz"
+  end
+
+  def test_invalid_opt_names
+    assert_empty @build.invalid_opt_names
+    assert_equal @bad_build.invalid_opt_names, %w[--without-abc --without-bas]
+  end
 end
diff --git a/Library/Homebrew/test/test_formula_installer.rb b/Library/Homebrew/test/test_formula_installer.rb
index 5b937d1df..18bd910a6 100644
--- a/Library/Homebrew/test/test_formula_installer.rb
+++ b/Library/Homebrew/test/test_formula_installer.rb
@@ -37,6 +37,7 @@ class InstallTests < Homebrew::TestCase
   end
 
   def test_a_basic_install
+    ARGV << "--with-invalid_flag" # added to ensure it doesn't fail install
     temporary_install(Testball.new) do |f|
       # Test that things made it into the Keg
       assert_predicate f.prefix+"readme", :exist?
diff --git a/Library/Homebrew/test/test_install.rb b/Library/Homebrew/test/test_install.rb
index 5d27d978b..e0a40b5d7 100644
--- a/Library/Homebrew/test/test_install.rb
+++ b/Library/Homebrew/test/test_install.rb
@@ -21,4 +21,10 @@ class IntegrationCommandTestInstall < IntegrationCommandTestCase
     assert_match "testball1 already installed, it's just not migrated",
       cmd("install", "testball2")
   end
+
+  def test_install_with_invalid_option
+    setup_test_formula "testball1"
+    assert_match "testball1: --with-fo is invalid for this formula and will be ignored!",
+      cmd("install", "testball1", "--with-fo")
+  end
 end